Hand-fed hammer drill



June 17 1924.

D. J. .HAFFORD 7 HAND FED HAMMER DRILL Filed Dec. 5, 1919 Patented dune i7, 1924,

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DANIEL J. HAFFORD, 0E CLEVELANIL OHIO, ASSIGNOR TO THE CLEVELAND ROCK DRILL COMPANY, 033 CLEVELAND, OHIO, A CORPORATION OF OHIO.

HAND-FED HAMMER DRILL.

Application filed December 5, 1919. Serial No. 342,655;

To all whom it may concern:

Be it known that I, DANIEL J. HAFFoRn, a citizen ofthe United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in -Hand-Fed Hammer Drills, of which the following is a full, clear, and exact description.

This invention relates to a hand fed stoping drill of the hammer piston type, and has for its chief objects to provide a feed which is more satisfactory than those used heretofore, which permits more rapid work, and which possesses also the element of safety in the sense that there is eliminated danger of injury to the operator resulting from the breakage of the drilling steel ein ployed ina stoping drill which is air fed.

Heretofore, stoping drills of the hammer piston type have either been air fed through the medium of a piston engaging in an air feed cylinder connected to the hammer cylinder, or the drill has been supported by a column, the drill being mounted in a cradle movable in a guide shell which is rigid with the column.

The use of an air feed drill is open to the objection that should the drilling steel break, the operator is in great danger of serious injury due to the air pressure on the piston of the feeding mechanism and the lack of sudden and positive control when breakage occurs.

The second method of feeding, wherein the drill is supported in a column generally interposed between the roof and bottom of the stope, is objectionable not only because the construction is cumbersome, heavy and expensive, but because it does not lend itself to rapidity of work.

These objections are overcome by my invention which comprises the combination of a stoping drill of the hammer piston type with a feed screw operatively connected to the hammer cylinder in line with its axis,

and in its more specific aspect the invention resides as well in certain details of the feed ing mechanism, as the latter is preferably constructed and applied to the hammer cyle inder or body of the drill proper.

In the accompanying sheet of drawings wherein I have shown an embodiment of my invention which operates with high elliciency, Fig. l is a vertical sectional view of 7 ing 15.

as here shown, 10 represents a hammer cyl-.

inder containing a reciprocating hammer piston 11 which is adapted to be reciprocated back and forth in the cylinder, and the blow of which is transmitted either through a tappet such as shown at 12, or

directly to the drilling steel 13 mounted in a rotary chuck 14, seated in a chuck hous- The chuck housing is flexibly connected through the medium of chuck bolts 16 and chuck bolt springs 17 to the end of the hammer cylinder 10, there being interposed between the chuck housing and hammer cylinder a piston bearing 18 and in this instance also steel rotating mechanism of wellknown type, and including a ratchet ring 19. As it is immaterial by what means the drillin steel is rotated, i. e. whether automatica ly or manually, this automatic rotating mechanism is not shown in detail and need not be further referred to.

At the base of the hammer cylinder 10 is a so-called valve block 20 and valve block button 21,- containing a valve to which air is supplied under the control .of a valve handle 22 from an air supply pipe 23, these latter parts being carried by a so-called hammer head 24:, to which the feeding mechanism is directly a plied, this hammer head constituting in eflEct part of the haimner cylinder.

Before taking up the feed mechanism it might be mentioned that with this type of drill, water is sometimes fed centrally through the drill, and in this instance it is designed to be supplied by a pipe 25, and conducted by a central tube up through the piston to the drilling steel which will have an openingat its drilling end for the discharge of the water.

Coming now to the part which more directly involves my invention, I provide a feed screw 26 directly in line with the axis of the drill, and attach it to the hammer cylinder or head 24, thereby producing a new method of feed and a new feed coir struction for a stoping drill of the reciprocating hammer piston type.

This feed screw is attached to the head 2 by having its inner end 26 screwed into a sleeve-like extension 24: of the head, and it is secured in position by a lock-nut 26 which engages the end or this extension. At the bottom or outer end of the feed screw is a center 27 which is mounted in a ine n ber 28 carried by a sleeve 29 surroun the lower portion of the feed screw and at tached to a housing 30 containing the no tuating mechanism for the feed screw, which housing surrounds the latter and ries a key 31 engaging in a key-way of the screw and serving to hold the screw and housing against relative rotation.

Supported in the housing through ballbearings 32 is a combined bevel gear and nut 33 threaded interiorly and engaging the threads of the screw so that as the combined gear and nut 33 is rotated the screw will be fed through the housing 30 either up or down, depending upon the direction of rotation of the part 83. This combined gear and nut 33 is engaged by a second bevel gear 34 mounted on a short shatt rotatably supported in a lateral extension 36 of the housing and projecting at right angl'es therefrom. On the outer end of this shaft is provided a handle which the operator turns in one direction to feed the drilling steel as the drilling progresses, and in the opposite direction when the operator desires to withdraw the drilling steel from the hole which he ha drilled. When the screw is lowered its maximum amount, its lower end engages the member 28 carrying the center, and the screw can be moved upwardly through the housing until a shoulder in the form of a nut 38 on the lower end of the screw engages an internal shoulder 39 of the housing 30. Fig. 1 shows the screw in its lowermost position, and Fig. 2 in its elevated position. It will be understood that when the screw is fed upward, the entire drill proper is elevated and the distance between the drill and housing 30 is varied, there being no connection between them other than that afforded by the sort-a itself.

With this stoping drill the operator con trols the rate of feed thereby providing a better and eater teed than the automatic air feed, and at the same time there is provided acompact construction far simpler than that embodied in a stoping drill mounted in a cradle movable along a drill supporting column.

Furthermore, the. screw feed mechanism provided on the specific type of tool herein described. renders the feeding operation remarkably easy. Due to the vibration set up by the hammer piston operating from one thousand to two thousand times per minute the feed screw actually floats in the feed nut, making it possible to turn the feed handle without appreciable resistance while the machine is in operation.

Having described my invention, 1 claim:

1. In a stoping drill, a drill body including a hammer cylinder containing a fluid actuated reciprocating hammer piston adapted to impart a blow to a drilling steel, in combination with a feed comprising a screw rigidly connected to the drill body in line with the axis thereof, means for actuating the screw, and thrust receiving means at the free end of said screw.

2.111 a stoping drill, a drill body ineluding a hammer cylinder containing a fluid actuated reciprocating hammer piston adapted to impart a blow to a drilling steel, in combination with a teed comprising a screw having a fixed operative connection with one end the drill hodyand means separate from the latter for bodily elevating or lowering the screw and drill body.

3. In a stoging drill, a drill body in cluding a hammer cylinder containing a fluid actuated reciprocating hammer piston adapted to impart a blow to a drilling steel, in combination with a feed comprising screw having at one end a iixed connection with the drill body, a housing surroundii the screw and having means for feeding L38 screw endwise through the housing.

l. In a stoping drill, a drill bod eluding a hammer cylinder contain 1 fiuid actuated reciprocating hammer piston adapted to impart a blow to a drilling steel, in combination with a teed conugrisin a screw rigidly connected at one end to e drill body, a housing surrounding the sc ew and carrying a center, a nut journaled in the housing and engaging the screw, and means projecting from the housing for rotating the nut.

5. ln a stoping drill. a drill body in cluding a hammer cylinder containing a fluid actuated reciprocating hammer p ston adapted to impart a blow to a drilling steel. in combination with a teed comprising screw rigidly connected. at one end to the drill body, a housing surrounding a portion of the screw, means for preventing relative rotation betwen the screw andhousing, and means for moving the screw endwise through the housing comprising a shaii. tending laterally from the housing, and gears connecting the shaft to the screw including an internally threaded gear surrounding and engaging the screw so as to serve as a nut.

In testimony whereof, I hereunto aflix my signature.

DANIEL J. lPlAFFQR L ill) 

